Method of making storage-battery electrodes.



PATENTED MAR. 3, 190s. T. A. EDISON. METHOD OF MAKING STORAGE BATTERY ELECTRODES.

APPLICATION FILED NOV. 2. 1905.

' Inventor 3 .fl. -a

Witn esses A ttorney UNITED STATES PATENT OFFICE.

moms A; EDISON, or L'LEWEliLYN PARK, ORANGE, NEW JERSEY, As sIcNoE 'ro EDISON s'romc BATTERY conPANr, or \vEsT ORANGE, NEW JERSEY, A CORPORATION OF NEW -.1 ERsEY.

METHOD OF MAKING STORAGE-BATTERY ELECTRODES.

No'l 880,979.

To all whom itmiag concern:

, Be it known thatL-ilnoims ALVA ED1soN.

,lL-{ llZGlLOf the .United States,- residing at Llewellyn Park, Orange, in the cou'ntypf 5 Essex andState of New Jersey, have invented aicertain new and useful Method of .Making Storage Battery Electrodes, of which the following is a description I My invention relates ,to, an improved ,10 nretlunl, of makin electrode elements for storagebatteries ofthe Edison type.

,.,.ln an application filed on ex 'endate herc with l dcscribe the improved electrode ele men't, constructed in accordance uith my ,15 present n,1ethod, and have quite elaborately explained the correct condition a hich should exist in the active material to secure the best results. Assuming the invention to be arricd out lll connection ith-the manufacture ,of the nickel mass and that metallic flakes of cobalt or cobalt-nickel alloy are, used thereuith, then, the best results are secured in practice when the conducting lihns or flakes, overlying and lapping 'umn one another, constitutc a close net-work of metallic condoctors, extending inall directions through- ,,out the mass, the active particles being closely compacted in engagement with the conductors so as to make good contact therewith, and proper circulation throughout the mass being afforded by providing 4 the mass with a net-pork of circulating channels extending in all directions and presenting a substantially predeterlrincd proportion of porosity relatively to the entire mass. As'l point out in my said application, these peculiar charzuateristics are secured when the clectrmlc' mass is subjected to special treatment before its introduction 40 within the containing, tubes, during its introductiou therein, and subsequent-mo such- Specification of Letters lE'atent. Application filed November 2, 1905. Serial No. 285,651.

Patented March 3, 11508.

scales are added and lntllllatOl-'llllXGGl there- .with, so as to adhere with sul'licient tenacity to the active particles as toprcvent segregation during manufacture. This special treatment presents important advantages in connection with the present invention, as will be explained. E

Second: The mass obtained in this way is now introduccd within perforated non-deformable inclosing pockets of su'liicient strength to resist the bulging or-disrupting strains encountered in actual use; and due to the tendency of the active material, to expand by absorption of the electrolyte, by electrolytic action, and by; the pressure of gasv generated within the 1nass'.,ln' thus filling the pockets with the mixture, of-active material and conducting flakes, I introduce the mixture within the, pockets in relatively small increments (from fifty to' a hundred increments, for eight grams of theimixture) and I subject each increment toone or more .tamping pressures, preferably as much as 20,0(lll'pounds per square inch, each pressure being substantially uniform, so that the mass throughout will be uniformly highly so compressed. As a result of this operation, the active particles will be crushed and deformed, so as to penetrate the films of sticky material, greatly extend the area fcontact with the conducting flakes andprcvent the smaller particles from being isolated or from making Imperfect or superficial contact with the conducting flakes, and the conducting flakes will be pressed together to overlapand form a net-work of conducting paths extending in all directions throughout the mass."

. The mass, as a whole, will furthermoro'he so closely and tightly consolidated as to prevent relative movement of the active mrticles with respect to the conducting flakes, and relative movement of the conducting ilakcs with respect to each other, as ".l lizn wlisg o'xts, cred that if such relatiye movement takes place the contact condition of the mass will be seriously impaired.

Third: After 'the mass has been thus packed in increments under high pressure preferably in slightly'alkaline water to prevent rust. This removal of the binder results in the formation within the mass of a.

.through the same, thereby allowing a large amount of the electrolyte to rapidly reach all parts of the mass to accommodate high discharge rates. These circulating channels also permit the mass to deform internally under swelling pressures, which, if the 'mass were perfectly consolidated, might burst the containing pockets. By forming a net-work of circulating channels in the active mass, as explained, I am enabled to very perfectly regulate the relative proportion of porosity, merely by regulatin the amount of sticky material admixed with the active particles in the-first instance. I In order that the invention-may be better understood, attention is directed tothe accompanying drawings, forming, part of this specification, and in which Figure 1, is a sectional dia rammatic view of a suitable apparatus for fi ling and ta1nping the active mass within the non-deformab e containing pockets, and Fig. 2, a front elevation partly 1n section of one of the complete electrode elements. In both of these views correspondin parts are represented by the same nuniera s of reference.

The pockets 1 are preferably tubular,

formed of a perforated strip of steel about .004 of an inch in thickness, first carefull plated with an alloy of cobalt and nickel: after which the strips are subjected to a welding temperature in a hydrogen atmosphere, being then formed into tubes. The tubes in question are preferably about four inches long, and about one-quarter of an inch in internal diameter. Surrounding the tube is a number of seamless nickel rings 2, fittin the and adding very materiall y to tube snugly,

of the tube in resisting bursting the strength strains. The filling of these tubes is preferably performed in a suitable apparatus of the general type disclosed in m application, filed October 14th, 1905, Seria and shown diagrammatically in Fig. 1. One or more of the tubes are placed in a suitable sectional holder 33, the sections of which.

' are tightly clamped together and closely en- I gage the tubes, so as to resist the enormous ursting strains encountered during the filling operation. The holder also comprises a base 4, for receiving the sections 3, and'provided with an extension 5, extending within the tubes and defining the extent of the tube which is to be turned over upon the compressed material, as will be understood.

' The sections 3 areprovided with recesses 6 for receiving the strenthening rings 2. Durin the tamping of t 10 material within the tu es, the latter will expand slightly into very close and intimate contact with the strengthenin rings, preventing any liability of shifting-of the latter. It will be understood that the sectional holder is provided with a series of chambers into which a number of the tubes will be snugly received, so that a lurality of tubes may be simultaneously led. Leading to each of the tubes is an auxiliary hopper 7, for guiding the successive increments of material therein. These increments are supplied from a main hopper 8, the bottom of which comprises a rotating shaft 9, haying pockets -l0-10 therein, the size of the latter depending upon the bulk of each increment. Cooperating with each tube, is a tamping plunger 11, formed with a weight 12,

of suitable mass and provided with a rack 13, with which engages a toothed cylinder 14. The cylinder 14 is so coordinated-with the rotary shaft 9" as to give one or two tamping operations on each increment. There is a" substantially greater number of teeth on the rack 13 than on the cylinder 14. As the cylinder 14 r0- tates the teeth on its periphery engage the rack 13, so as to lift the plunger 11 to an extent depending upon the number of teeth on the cylinder, and when the last tooth on the cylinder leaves the rack 13, the plunger will drop. The rack 13 is of sufiicient length to permit the teeth of the cylinder 14 to give at all times a complete lifting movement to the plun er, so that it will be understood that whet ier the plunger is engaging an more 'ment near the bottom of the tube or an in crement when the tube is wholly filled, the first tooth of the cylinder will en age some one tooth on the rack, will then lift the rack through a distance corresponding to the num-, ber of the teeth on the cylinder, when theplunger'will drop. As the tube is filled up the cylinder teeth which are lower and lower upon the rack, but the rack'will always be lifted up until eachof the teeth of the cylinder has engaged one of the teeth on the rack and therefore the plunger will always drop the same distance and therefore impart the same tamping blow. j

In practice I permit theplungers Weighing three pounds each to drop a distance of five inches; and the diameter of the plungers is teeth will engage with rack about one-quarter of an inch. In this way I deliver a tamping blow of about one thousand pounds on each increment, since the plungers are brought almost instantaneously to rest. At the same time, by imparting a very reat pressure in only a fraction of a secom the plungers although of small diameter,-have no opportunity of becoming distorted, or breaking, as would be the case if the same pressure were a in a hydraulic press. I sually provis1on is made, as disclosed in my said application last referred to, for arresting the operation of plied gradually, as-

eenf

ll xll i e m m e' intro fstna'll increments ".d

59 tel-kl) thereby qbnsolidgting the mrss new formed 5f the "mass presen ts fvryimn iactl kirti'clsfof gran-mes karimrisla:

containing minute connected bodies of the sticky material as (llS} )l:LC e (l by the pressure.

\. we di n i age- 16 a sticky material is, thel efgne, impiyrft'an t for lawn-fold purpose" -'e: tbiau's'e 3 the "eon- 'pilyijnndel greet pressure,v and .t r l??? 'centl or'r'ndre'df the entire'niass. ense'of mass -constitutes a porous coherent .bod

about as hard as soap-stone and cutting wit 1' ing of the active particles but any defo'r'ma tionis permitted interna y by reason ofthe presence of the net work of circulating channels, and the ressure on the walls of the containerT'is insu cient to disrupt-the same.- i This swellingl s not suflicient to close up the circplating c male and does not, therefore,

' interfere with the perfect and re id circulation of the electrolyte, nor with t e escape of gas. As a matter 'of fact, the particles .of

nickel hydroxid are themseliesiguite pbrens' a one re 1e 1 but not to a suflicie'nt extent,

upon, to permit the'elect'rolyte to eirculaite with sufficient rapidity throughoutthe mass;

butby providing the massfwithfoonnected passages extending throughout the same, the electrolyte 1S enab ed to' readily and rapidly penetrate the mass in an directions, so that the porosity off each article has only to be. rehedupon to furnis the necessary-supply.

' ing flaP'es-wiil be caused-t9 a here to the {1.6% l

of the solution to its own minutemass.

Having now described In invention, what I claim as new therein and esire to secure by Letters Patent is-as follows: 1

1. The method of making electrode elements which consistsin introducing a mixture of particles of active material and flake likeconducting material .within non-deform able inclosing pockets, and in. applying a pressure to such material suiiicicnt to crush' or. deform the active particles and cause f them to substantiallylfollow the contour of the conducting flakes, as and for the purposes setforth.

2. The method of making'electro'de ele- 'ments', which consists in introducing within a non-deformable inclosing' pocket in suc-r cessive small increments, a mixture of part1- cles of'active material and flake-like conducting material, and in applying to each incre' ment after its introduction suificient pressure to deform or crush the active )articles" and cause them to substantially. follow the" contour of the conducting flakes, as and for the purposes set forth. 1 3. The method of making electrode, elements, which includes adding a sticky binder to the active particles, so as to substantially tothe sticky mass flake-like conductii material, whereby the conducting ilakesw' be caused to adhere'to the active particles in introducing the mixture so obtained within coat the surfaces of the latter, in then adding.

nondeformable inclosing pockets, and in applying to the nixturesuflicient pressure to orce the active particles through the films formed by the binder, dis lac' the'latter into the minute interstices ibrme within the mass. and spreading the active particles with respect to and upon the surfaces presented by the conducting flakes, as and for the purposes set forth; T

4. The method of making electrode elements, which includes adding a sticky binder to the active particles, so as to substantially coat the surfaces of the latter,'-in then adding to the sticky mass flake-like conducting ina 'terial, whereby the conducting flakes will be caused to adhere'to the active particles, in introducin the mixture so obtamedd'nsuccessive sma increments within non-deformable inclosing peck ets,and in applying to each crement suflicient pressure to force the airthe blnder, displacing the latter into the numite intersticesformedwithin the mass and spreading theactive particles with res met to 'andupon the surfaces by the con ucting o flakes, asand'for the purposes setforth. "5. The method of making electrode ole-= ments, which consists in adding.a sti cky binder to the active particles, so as to substantially coat the surfaces of thcwla'tten 'in then adding to the sticky mass flake-like conducting material, whereb the conduct-.

tive' particles, in introducing the mixture so obtained within non-deformable inclosing i pocl'ets. and in applying to the mixture su iiicien t pressure to force the active particles through the films formed by the binder, dis- )lacing the latter into the minute interstices io'rmed within the mass, andspreading the 5 .active particles with respect to and upon the surfaces presented bylthe conducting flakes, and in finally removing the binder so as to thereby resultin the formation within the mass of a net-work of circulati channels, as

and for the purposes set forth.

6. The method of making' electrode elements}. which consists "in adding-a -stick'y hinder, to the active particles, 'soas tofsub-"f stantiallv'coat the surfaces oi the'latteifl'jn then adding to the sticky n1ass,flake-like con- 1 ducting -'ihaterial', whereb the conducting fiates will be caused to a A ere to the active particles, lI l' introducing them x ur .sofob- 1 norbdeformable inclosing" pgie'kets"and1 in alp plying to each incrementsufficient to force the active particles through t 'e films mass and spreading the active particleswith respect toaud upon the surfaces by the 'con- I ducting flakes," and infinal 'removmg'the A binder so as to thereby resu tin the formatien within" the mass of a net-work ofi circu- 1 3o tive articles through the filn1s'.formed bytained in successive small increments 1-20:

formed by the binder, dis lacin 'th'elatter" into the minute interstices orme Hvrthm'the 13s suo,979

- to be present in the active mass of a storage battery electrode, which consists in adding to the active particles a predetermined amount of a soluble viscous material, then in adding a flake-like conducting material thereto the in introducing the mixture within t fillltflbi? inclosing pocket, then-in applying pressure LO the mass, and finall ,in removing the Vi cous material, whereiiy the spaces previously occupied by the same will exist as a net-Work of circulating channels extending hi all directions throughout the mass, as" and for h purposes set forth. 1

8. The me. od of making storage battery electrodes, 'which consists in introducing in successive and very small increments, active material Within a non-deformable inclosing pocket, and in subjecting each increment to one or more tamping blows delivered by a weight falling always from the same height above each increment, as and for the purposes set forth. v r

This specification signed and witnessed this 31st day of October 1905.

THOMAS A. EDISON.

Witnesses FRANK L. DYER, ANNA R. KLEHM. 

